Health and safety: How loud is too loud?

Piling and drilling equipment can be noisy but is it just something the industry has to put up with? Anne Baxter doesn’t believe it should be and urges the industry to take precautions

Noise may be part of the job in ground engineering but there are also limits where noise is no longer “part of the job” and can actually start to damage hearing. But the solution to noise at work – like other issues in the drilling industry – is not easily resolved.

Noise is essentially any unwanted sound and, in the case of drilling, it is what is produced by mechanical movement, impact and vibration. Noise of any kind, whether at work or leisure, can cause hearing loss, which may be either temporary or permanent.

People often experience temporary deafness after leaving a noisy place and many are probably familiar with that “ringing in the ears” feeling when leaving a concert or nightclub. In these circumstances hearing may recover within a few hours but, nonetheless, the hearing will have been damaged at some level and this should never be ignored.

Continued exposure to noise at these levels could permanently damage hearing but it can also be can be caused immediately by sudden, extremely loud, explosive noises, such as from a standard penetration test (SPT) or chapping casing.

Any hearing loss is an issue and its causes are of concern, however, it is the gradual hearing loss that occurs as a result of prolonged exposure to noise that is particularly worrying. Workers may not notice the damage caused by noise in the workplace but in time this combines with hearing loss due to ageing.

In many instances, the first signs may be other family members complaining about the television being too loud or that proper conversation in the pub is a struggle, while others have no problem. Over time, everything becomes muffled and it becomes difficult to catch sounds like “t”, “d” and “s”, so concentration is required to join a conversation or conversation is avoided and individuals become isolated. Hearing loss isn’t the only problem – there is also the risk of developing tinnitus with symptoms such as ringing, whistling, buzzing or humming in the ears, which is intrusive and can lead to disturbed sleep, and all the health implications that itself brings.

Legislation covering noise at work is not new – the Control of Noise at Work Regulations 2005 came into force for industries, including drilling, on 6 April 2006. It states employers must assess the risk to workers’ health from noise and guidance is available to download free of charge from HSE’s web site.

Noise is typically measured by an electronic sound meter, with the results indicated in Decibels dB(A). The Decibel scale is a logarithmic scale which means 90dB(A) is 10 times the intensity (loudness) of 80dB(A) and 100 times 70dB(A). Roughly every 3dB(A) means a doubling of the loudness.

Legislation also states that the level at which employers must provide employees with information and training is 80dB(A) and hearing protection must be provided free of charge when requested. The level at which employers must provide hearing protection is 85dB(A) on a daily or weekly average exposure and the wearing of hearing protection must be enforced. There is also a maximum exposure limit of 87dB(A) above which workers must not be exposed.

In this context, when are drillers exposed to noise? It could start with a radio blaring while driving to site or employees using their phone to listen to music with the ear pods in during working time. Then there are the noise levels produced during cable percussion drilling, which varies throughout the day. With many factors affecting the noise produced it is not possible to state that a cable percussion rig, or indeed any other rig, will produce “x” noise levels throughout the day. Factors such as maintenance of the rig can have a significant effect; metal rattling off metal while the rig engine is ticking over, although probably a low level noise it still adds to the daily noise dose. However, the environmental conditions can also have a significant affect, for example, low cloud can reflect noise back down towards the operation as can hard surfaces such as buildings, site vehicles or rock faces. Then there is the effort required to drill through the strata, which may result in drillers setting the rig engine to maximum revs rather than adjust it to the most appropriate level.

It is clear then that it is impossible to determine noise levels on a practical basis as it would require all drillers to measure noise levels throughout the day to get accurate levels. Nonetheless, there is a good rule of thumb method that is pretty accurate and is easily applied: if voices need to be raised at 2m apart – roughly two arm lengths – the noise will be in excess of 85dB(A) and hearing protection must be used.

Despite the risks, some drillers won’t wear their hearing protection with excuses such as “I need to hear what is happening down the hole,” or, more bizarrely, “I’m already deaf so it’s too late”. In this latter case employers have a higher duty of care to protect the remaining hearing capacity. There are no real acceptable excuses. Employees must wear hearing protection when required, look after it, inspect it before use, make sure it fits correctly – change if defective and report defects to employer and keep it clean.

Hearing deteriorates with age so when it is inevitable that at retirement we won’t be able to hear as well as we did when we entered the industry. That said, if hearing protection is worn at the start of a career in the ground engineering sector, workers will at least be able to hear as well as the older person without hearing protection and will become accustomed to the hearing protection. After all you want to be able to hear what they are saying about you at your retirement party!

This article was written by Anne Baxter who is chair of the British Drilling Association

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